Undercooling Measurements during Alloy Solidification

该程序是对金属快速凝固过程中微观结构的基础研究。测量了分离液体和固体的平面界面的运动速度。采用激光脉冲在沉积在绝缘衬底上的薄膜上产生一维熔化图案。确定了界面运动、过冷和溶质捕获。实验数据应该为界面速度/过冷函数的理论提供定量检验。本研究考察了快速凝固处理技术所产生的非平衡条件，如激光熔化、离子注入和等离子喷涂。目标是开发改进的预测能力，材料的微观结构和化学分离的结果，从加工。

This program is a fundamental study of the microstructure derived from rapid solidification processing of metals. The velocity of motion of the planar interface that separates the liquid and solid is measured. Laser pulsing is employed to create a one dimensional melting pattern on thin films deposited on insulating substrates. Interface motion, undercooling, and solute trapping are determined. The experimental data should provide a quantitative test of theories for the interface velocity/undercooling function. %%% This research examines non-equilibrium conditions created by rapid solidification processing techniques, such as laser melting, ion implantation, and plasma spraying. The goal is to develop improved predictive capabilities for the material microstructure and chemical segregation that results from the processing.